You pay for quality, don't you? That's the theory, at least, and premium fuels are the 'quality' product at the filling stations.
Claims of better fuel economy, improved performance and the cleaner engines are hard to ignore, so for those willing to fork out an extra 9p per litre for higher-octane products like Shell V-Power, Esso Supreme and BP Ultimate, it sounds like a price worth paying.
Read on to find out if they are.